qt 数据库操作实例

QT       += core sql

#include <QSqlQuery>

 QStringList drivers = QSqlDatabase::drivers();
    foreach(QString driver, drivers)
        qDebug() << driver;

    //添加数据库驱动
    QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
    //设置数据库名称
    db.setDatabaseName(":memory:");
    //打开数据库
    if(!db.open())
    {
        return false;
    }

    //以下执行相关sql语句
    QSqlQuery query;

    //新建student表，id设置为主键，还有一个name项
    query.exec("create table student(id int primary key,name varchar)");

    //向表中插入3条记录
    query.exec("insert into student values(1,'xiaogang')");
    query.exec("insert into student values(2,'xiaoming')");
    query.exec("insert into student values(3,'xiaohong')");
    //查找表中id >=2 的记录的id项和name项的值
    query.exec("select id,name from student where id >= 2");//query.next()指向查找到的第一条记录，然后每次后移一条记录
    while(query.next())
    {
        //query.value(0)是id的值，将其转换为int型
        int value0 = query.value(0).toInt();
        QString value1 = query.value(1).toString();
        //输出两个值
        qDebug() << value0 << value1 ;
    }